We discuss the case of a 5-month-old male British Shorthair referred to our hospital following the detection of a heart murmur during a routine vaccination appointment. Two-dimensional echocardiography revealed a 1.18 mm ventricular septal defect (VSD) located immediately below the aortic valve, without signs of secondary cardiac remodeling. Given the absence of cardiac dysfunction, no treatment was administered, and the cat was periodically monitored over the next 2 years. Echocardiography at 29 months of age revealed no signs of the VSD. Future studies are needed to increase the evidence base for spontaneous VSD closure in small animals.

A 6-month-old male Ragdoll cat presented with exercise intolerance. On physical examination, there was a grade 2/6 systolic murmur at the right apex. Diagnostic tests, including SpO2 measurement, blood tests, radiography, echocardiography, contrast echocardiography, and electrocardiography, were performed. Severe right atrial dilation, tricuspid valve leaflets and orifice displacement, right ventricular atrialization, septal leaflet adherence, anterior leaflet tethering, and right atrioventricular junction dilation were noted on echocardiography, alongside a right-to-left atrial septal defect. Cor triatriatum dexter and left ventricular aneurysm were observed. We diagnosed this case as having Ebstein anomaly with rare congenital heart deformities; which is rare in cats.